Another week, another batch of links and sciency tidbits! Tomorrow I’m leaving for vacation, so I might not be able to update much (and I’ve been pretty busy this week), so there is plenty to keep you busy here: Making sperm in the lab, little squids that make big sperm, killing sperm to stop malaria, the costs of getting a date, male breast cancer, and how to talk to your kids about sex. Oh, and just for fun, a video of animals attempting copulation with…well, they’re not doing it right.
- I’m sure that many of you have wondered at one time or another how you might go about making your own sperm (outside of the normal route, that is). What ingredients would you need?
Scientists in Japan have figured out a way to make the precursor cells for making sperm. They coaxed mouse embryonic stem cells into becoming primordial germ cells (PGCs), which can then make sperm.
The researchers used mice that don’t make their own sperm (a type of mutant also made in the lab) and transplanted them with the home-grown PGCs. 8-10 weeks later: voila! The mice made sperm that could be used to fertilize eggs. The results teach us a lot about how sperm get made. Similar procedures could be used in the future to help men with infertility, by using adult stem cells instead of embryonic ones.
- Usually, sperm is pretty cool (see above), but sometimes letting those little guys fertilize eggs can be a problem. For instance, when those sperm and eggs come from disease-carrying mosquitoes.
Scientists at Imperial College London have figured out a way to create spermless mosquitoes (Anopheles gambiae). When mosquito females mate, chemicals in the male’s semen take away her desire to mate again, ever. If spermless males were released in the wild, females that mated with them wouldn’t be able to make any malaria-trafficking babies.
The sterile male technique is not a new idea. The key to this new research is that the sterile males seem to do just as well at getting mates (and keeping them from re-mating) as normal males, which hasn’t been the case with other sterile-male experiments.
- Males of many species need to show off for the ladies if they’re going to get a chance at mating and passing on their genes. A desert bird, the houbara bustard, is no exception. Males of this species have elaborate courtship displays to woo females. New research from the University of Burgundy in France shows that showy males pay a big price. Males with the most extravagant displays had “burnt-out” ejaculates and aged faster.
- While we’re on the subject of sperm, here’s a new one for you. Spear squid make two different kinds of sperm, depending on whether the male is large or puny.The larger males are more attractive to females and will mate with them the normal way, depositing their sperm inside of her to fertilize her eggs. Smaller, more wimpy males don’t have a shot at this kind of mating, so they sneak in and deposit their sperm at a spot on the female outside of where she will release her eggs.
Each type of male has sperm that are best suited for the male’s mating strategy. Large males have smaller sperm that do best inside the female’s reproductive tract. Small males have large sperm that fare best out in the open. This study was done by Yoko Iwata and colleagues at the University of Tokyo.
By now, I’m sure you all know that breast cancer is a big deal. But, as the use of a pink ribbon for breast cancer awareness indicates, breast cancer is thought of as a woman’s disease. While it’s true that the overwhelming majority of breast cancer cases are in women, men can also get this type of cancer (a famous case is Montel Williams, though it turns out his tumor was benign).
Recently, a 26-year-old man named Raymond Johnson was diagnosed with breast cancer. Bad news, right? As if that wasn’t bad enough, he was then hit with more bad news. Medicaid, the insurance was was using, would cover breast cancer treatments, but only if he was a woman. For more info, see this article.
- The sex talk. Parents dread it, kids get embarrassed by it. But once it’s over, it’s over, right? Wrong, experts say. The “sex talk” should be an ongoing discussion with your child about everything from what genitals are for to contraception. See this article for more.
- Just for laughs, I thought I’d throw in a link to a “Funniest Home Videos” type thing of animals trying to get it on with various other animals, humans, and objects. That turtle at the end is the best!